1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
//use std::borrow::Cow;
//use std::ffi::CStr;
//use std::os::raw::c_char;
//
//static B: [u8; 10] = [99, 97, 114, 114, 121, 116, 111, 119, 101, 108];
//static C: [u8; 11] = [116, 104, 97, 110, 107, 115, 102, 105, 115, 104, 0];
//
//fn main() {
// let a = 42;
// let b: String;
// let c: Cow<str>;
//
// unsafe {
// let b_ptr = &B as *const u8 as *mut u8;
// b = String::from_raw_parts(b_ptr, 10, 10);
//
// let c_ptr = &C as *const u8 as *const c_char;
// c = CStr::from_ptr(c_ptr).to_string_lossy();
// }
//
// println!("{} {} {}", a, b, c);
//}
//fn main() {
// let a: i64 = 42;
// let a_ptr = &a as *const i64;
// let a_addr: usize = unsafe { std::mem::transmute(a_ptr) };
//
// println!("{} {:p} 0x{:x}", a, a_ptr, a_addr + 7);
//}
//fn main() {
// let ptr = 42 as *const Vec<String>;
//
// unsafe {
// let new_addr = ptr.offset(4);
// println!("{:p} => {:p}", ptr, new_addr);
// }
//}
//fn main() {
// let password = String::from("lousy");
// dbg!(is_strong(password));
// dbg!(is_strong("breakage"));
//}
//
//fn is_strong<T: AsRef<str>>(password: T) -> bool {
// password.as_ref().len() > 5
//}
//use std::mem::drop;
//
//fn main() {
//// let a: i32 = 40;
//// let b: Box<i32> = Box::new(60);
//// dbg!(a + *b);
//
// let a = Box::new(1);
// let b = Box::new(1);
// let c = Box::new(1);
//
// let result1 = *a + *b + *c;
//
// drop(a);
// let d = Box::new(1);
// let result2 = *b + *c + *d;
//
// println!("{} {}", result1, result2);
//}
fn main() {
let mut n_nonzero = 0;
for i in 0..10_000 {
let ptr = i as *const u8;
let byte_at_addr = unsafe { *ptr };
if byte_at_addr != 0 {
n_nonzero += 1;
}
}
println!("{}", n_nonzero);
}
|
